An earthwork, dike, ditch, or bank that is created in a straight line, not curving around to form an enclosure. Such earthworks were of various lengths and created for various purposes. Some Bronze and Iron Age examples may be ranch boundaries with no defensive value, but later Iron Age and the post-Roman Dark Age may be either boundary markers or defense works. Many of these later dikes cut across communication route or lines of easy access, and would have been an effective obstacle against chariots or wheeled vehicles.